1. Field of the Invention
The present invention relates to pigment grinding vehicles and, more particularly, to resinous products suitable for such use. In another aspect, the invention relates to cationic electrocoating employing paints containing novel pigment grinding vehicles.
2. Brief Description of the Prior Art
In the formation of paint compositions, and especially electrodepositable paint compositions, an important factor is the introduction of pigments into the coating composition. The pigments are typically ground in a pigment grinding vehicle which acts as a dispersing agent to form a paste, and the resultant pigment paste is incorporated into the coating composition to give the coating composition proper color, opacity, application and film properties.
Unfortunately, many of the pigment pastes for electrodeposition are mixtures of water-soluble soaps or resins which are not electrodepositable. These pastes remain in the aqueous phase where they pose serious effluent problems.
The present invention overcomes this problem by providing a pigment grinding vehicle which can be made electrodepositable and codepositable with the vehicle resin of the paint.